PLA/PLGA nanoparticles prepared by nano spray drying

Novel rivaroxaban-loaded microsphere systems with different surface microstructure for enhanced oral bioavailability

This study compares rivaroxaban-loaded polymeric microsphere systems with three types of surface microstructure. Three types of polymeric microspheres loaded with rivaroxaban were fabricated using a spray-drying technique: solvent-evaporated, surface-attached, and solvent-wet microspheres, depending on whether the drug and additives used are soluble in the solvent. The solvent-evaporated and surface-attached microspheres had a rivaroxaban/polyvinylpyrrolidone/sodium lauryl sulfate (SLS) weight ratio of 1/0.25/2.2, and the solvent-wetted microspheres contained rivaroxaban/polyvinyl alcohol/SLS in equal weight ratio (1/0.25/2). The physicochemical properties of the microspheres were evaluated using scanning electron microscopy, powder X-ray diffraction, differential scanning calorimetry, and particle size distribution analysis. The aqueous solubility and dissolution rate of rivaroxaban in the three types of microspheres were compared to those of the drug powder. The solvent-evaporated, surface-attached, and solvent-wetted microspheres were approximately 208, 140, and 172 times as soluble as the drug powder, and the final dissolution rate (120 min) was approximately 5, 2, and 4 times that of the drug powder, respectively. In addition, the oral bioavailability increased by approximately 2, 1.3, and 1.6 times compared to that of the drug powder (area under drug concentration-time curve: 2101.3 ± 314.8, 1325.2 ± 333.3, and 1664.0 ± 102.6 h·ng/mL, respectively). Finally, the solvent-evaporated microspheres showed the greatest improvement (solvent evaporating microspheres > solvent wetted microspheres > surface-attached microspheres ≥ drug powder). Therefore, the solvent-evaporated microspheres may represent a novel oral dosage form that improves the oral bioavailability of rivaroxaban, a poorly soluble drug.

Factors Affecting the Synthesis of Bovine Serum Albumin Nanoparticles Using the Desolvation Method

Currently, protein-based nanoparticles are in high demand as drug delivery systems due to their exceptional qualities, including nontoxicity, nonantigenicity, and biodegradability. Other qualities include high nutritional value, abundance of renewable resources, excellent drug binding capacity, greater stability during storage and in vivo, as well as ease of upgrading during manufacture. Examples of protein suitable for this purpose include ovalbumin (OVA) derived from egg white, human serum albumin (HSA), and bovine serum albumin (BSA). To create albumin nanoparticles, six different processes have been investigated in depth and are frequently used in drug delivery systems. These included desolvation, thermal gelation, emulsification, NAB technology, self-assembly, and nanospray drying. Several experimental conditions in the synthesis of albumin nanoparticles can affect the physicochemical characterization. Therefore, this study aimed to provide an overview of various experimental conditions capable of affecting the physicochemical characteristics of BSA nanoparticles formed using the desolvation method. By considering the variation in optimal experimental conditions, a delivery system of BSA nanoparticles with the best physicochemical characterization results could be developed.

Degradable Polymeric Bio(nano)materials and Their Biomedical Applications: A Comprehensive Overview and Recent Updates

Degradable polymers (both biomacromolecules and several synthetic polymers) for biomedical applications have been promising very much in the recent past due to their low cost, biocompatibility, flexibility, and minimal side effects. Here, we present an overview with updated information on natural and synthetic degradable polymers where a brief account on different polysaccharides, proteins, and synthetic polymers viz. polyesters/polyamino acids/polyanhydrides/polyphosphazenes/polyurethanes relevant to biomedical applications has been provided. The various approaches for the transformation of these polymers by physical/chemical means viz. cross-linking, as polyblends, nanocomposites/hybrid composites, interpenetrating complexes, interpolymer/polyion complexes, functionalization, polymer conjugates, and block and graft copolymers, are described. The degradation mechanism, drug loading profiles, and toxicological aspects of polymeric nanoparticles formed are also defined. Biomedical applications of these degradable polymer-based biomaterials in and as wound dressing/healing, biosensors, drug delivery systems, tissue engineering, and regenerative medicine, etc., are highlighted. In addition, the use of such nano systems to solve current drug delivery problems is briefly reviewed.

Research Progress on Immunomodulatory Effects of Poly (Lactic-co- Glycolic Acid) Nanoparticles Loaded with Traditional Chinese Medicine Monomers

Immunomodulatory mechanisms are indispensable and key factors in maintaining the balance of the environment in humans. When the immune function of the immune system is impaired, autoimmune diseases occur. Excessive body fatigue, natural aging of the human body, malnutrition, genetic factors and other reasons cause low immune function, due to which the body is prone to being infected by bacteria or cancer. Clinically, the existing therapeutic drugs still have problems such as high toxicity, long treatment cycle, drug resistance and high price, so we still need to explore and develop a high efficiency and low toxicity drug. Poly(lactic-co-glycolic acid) (PLGA) refers to a nontoxic polymer compound that exhibits excellent biocompatibility. Traditional Chinese medicine (TCM) monomers come from natural plants, and have the characteristics of high efficiency and low toxicity. Applying PLGA to TCM monomers can make up for the defects of traditional dosage forms, improve bioavailability, reduce the frequency and dosage of drug use, and reduce toxicity and side effects, thus having the characteristics of sustained release and targeting. Accordingly, PLGA nanoparticles loaded with TCM monomers have been the focus of development. The previous research on drug loading advantages, preparation methods, and immune regulation of TCM PLGA nanoparticles is summarized in the following sections.

Drug release from PLGA microparticles can be slowed down by a surrounding hydrogel

This study aimed to evaluate and better understand the potential impact that a layer of surrounding hydrogel (mimicking living tissue) can have on the drug release from PLGA microparticles. Ibuprofen-loaded microparticles were prepared with an emulsion solvent extraction/evaporation method. The drug loading was about 48%. The surface of the microparticles appeared initially smooth and non-porous. In contrast, the internal microstructure of the particles exhibited a continuous network of tiny pores. Ibuprofen release from single microparticles was measured into agarose gels and well-agitated phosphate buffer pH 7.4. Optical microscopy, scanning electron microscopy, differential scanning calorimetry, X-ray powder diffraction, and X-ray μCT imaging were used to characterize the microparticles before and after exposure to the release media. Importantly, ibuprofen release was much slower in the presence of a surrounding agarose gel, e.g., the complete release took two weeks vs. a few days in well agitated phosphate buffer. This can probably be attributed to the fact that the hydrogel sterically hinders substantial system swelling and, thus, slows down the related increase in drug mobility. In addition, in this particular case, the convective flow in agitated bulk fluid likely damages the thin PLGA layer at the microparticles' surface, giving the outer aqueous phase more rapid access to the inner continuous pore network: Upon contact with water, the drug dissolves and rapidly diffuses out through a continuous network of water-filled channels. Without direct surface access, most of the drug "has to wait" for the onset of substantial system swelling to be released.

High energy ball milling vs. nano spray drying in the development of supersaturated systems loaded with bosentan

In this study, high energy ball milling and nano spray drying were used to prepare amorphous solid dispersions of bosentan in copovidone for the first time. In particular, the impact of this polymer on the bosentan amorphization kinetics was investigated. Copovidone was shown to facilitate the amorphization of bosentan upon ball milling. As a result, bosentan was dispersed in copovidone at the molecular level, forming amorphous solid dispersions, regardless of the ratio of the compounds. The similarity between the values of the adjustment parameter that describes the goodness of fit of the Gordon-Taylor equation to the experimental data (K = 1.16) and that theoretically calculated for an ideal mixture (K = 1.13) supported these findings. The kind of coprocessing method determined the powder microstructure and the release rate. The opportunity to prepare submicrometer-sized spherical particles using nano spray drying was an important advantage of this technology. Both coprocessing methods allowed the formation of long-lasting supersaturated bosentan solutions in the gastric environment with maximum concentrations reached ranging from four (11.20 μg/mL) to more than ten times higher (31.17 μg/mL) than those recorded when the drug was vitrified alone (2.76 μg/mL). Moreover, this supersaturation lasted for a period of time at least twice as long as that of the amorphous bosentan processed without copovidone (15 min vs. 30-60 min). Finally, these binary amorphous solid dispersions were XRD-amorphous for a year of storage under ambient conditions.

Core-Shell Structured PLGA Particles Having Highly Controllable Ketoprofen Drug Release

The non-steroid anti-inflammatory drug ketoprofen (KP) as a model molecule is encapsulated in different poly(lactide-co-glycolide) (PLGA) nanostructured particles, using Tween20 (TWEEN) and Pluronic F127 (PLUR) as stabilizers to demonstrate the design of a biocompatible colloidal carrier particles with highly controllable drug release feature. Based on TEM images the formation of well-defined core-shell structure is highly favorable using nanoprecipitation method. Stabile polymer-based colloids with ~200-210 nm hydrodynamic diameter can be formed by successful optimization of the KP concentration with the right choice of stabilizer. Encapsulation efficiency (EE%) of 14-18% can be achieved. We clearly confirmed that the molecular weight of the stabilizer thus its structure greatly controls the drug release from the PLGA carrier particles. It can be determined that ~20% and ~70% retention is available with the use of PLUR and TWEEN, respectively. This measurable difference can be explained by the fact that the non-ionic PLUR polymer provides a steric stabilization of the carrier particles in the form of a loose shell, while the adsorption of the non-ionic biocompatible TWEEN surfactant results in a more compact and well-ordered shell around the PLGA particles. In addition, the release property can be further tuned by decreasing the hydrophilicity of PLGA by changing the monomer ratio in the range of ~20-60% (PLUR) and 70-90% (TWEEN).

Poly(lactic-co-glycolic) Acid (PLGA) Nanoparticles and Transdermal Drug Delivery: An Overview

BACKGROUND

Biodegradable polymeric nanoparticles have garnered pharmaceutical industry attention throughout the past decade. PLGA [Poly(lactic-co-glycolic acid)] is an excellent biodegradable polymer explored for the preparation of nanoparticles that are administered through various routes like intravenous and transdermal. PLGA's versatility makes it a good choice for the preparation of nanoparticles.

OBJECTIVE

The main objective of this review paper was to summarize methods of preparation and characterization of PLGA nanoparticles along with their role in the transdermal delivery of various therapeutic agents.

METHODS

A literature survey for the present review paper was done using various search engines like Pubmed, Google Scholar, and Science Direct.

RESULTS

In comparison to traditional transdermal administration systems, PLGA nanoparticles have demonstrated several benefits in preclinical investigations, including fewer side effects, low dosage frequency, high skin permeability, and simplicity of application.

CONCLUSION

PLGA nanoparticles can be considered efficient nanocarriers for the transdermal delivery of drugs. Nevertheless, the clinical investigation of PLGA nanoparticles for the transdermal administration of therapeutic agents remains a formidable obstacle.

Long-term release of bioactive interferon-alpha from PLGA-chitosan microparticles: in vitro and in vivo studies

Effective cytokine treatments often require high- and multiple-dose due to the short half-life of these molecules. Here, porcine interferon-alpha (IFNα) is encapsulated in PLGA-chitosan microparticles (IFNα-MPs) to accomplish both slow drug release and drug protection from degradation. A procedure that combines emulsion and spray-drying techniques yielded almost spherical microspheres with an average diameter of 3.00 ± 1.50 μm. SEM, Microtrac, and Z-potential analyses of three IFNα-MP batches showed similar results, indicating the process is reproducible. These studies supported molecular evidence obtained in FTIR analysis, which indicated a compact structure of IFNα-MPs. Consistently, IFNα release kinetics assessed in vitro followed a zero-order behavior typical of sustained release from a polymeric matrix. This study showed that IFNα-MPs released bioactive molecules for at least 15 days, achieving IFNα protection. In addition, pigs treated with IFNα-MPs exhibited overexpression of IFNα-stimulated genes 16 days after treatment. Instead, the expression levels of these genes decreased after day 4th in pigs treated with non-encapsulated IFNα. In vitro and in vivo experiments demonstrated that the formulation improved the prophylactic and therapeutic potential of IFNα, accomplishing molecule protection and long-term release for at least two weeks. The procedure used to obtain IFNα-MPs is reproducible, scalable, and suitable for encapsulating other drugs.

Obtaining and Characterizing Andean Multi-Floral Propolis Nanoencapsulates in Polymeric Matrices

Propolis is a substance with significant anti-inflammatory, anticancer, and antiviral activity, which could be used more efficiently at the nano level as an additive in the food industry. The aim was to obtain and characterize nanoencapsulated multi-floral propolis from the agro-ecological region of Apurimac, Peru. For nanoencapsulation, 5% ethanolic extracts propolis with 0.3% gum arabic and 30% maltodextrin were prepared. Then, the mixtures were dried by nano spraying at 120 °C using the smallest nebulizer. The flavonoid content was between 1.81 and 6.66 mg quercetin/g, the phenolic compounds were between 1.76 and 6.13 mg GAE/g, and a high antioxidant capacity was observed. The results of moisture, water activity, bulk density, color, hygroscopicity, solubility, yield, and encapsulation efficiency were typical of the nano spray drying process. The total organic carbon content was around 24%, heterogeneous spherical particles were observed at nanometer level (between 11.1 and 562.6 nm), with different behaviors in colloidal solution, the thermal gravimetric properties were similar in all the encapsulates, the FTIR and EDS analysis confirmed the encapsulation and the X-ray diffraction showed amorphous characteristics in the obtained material; stability and phenolic compound release studies indicated high values of 8.25–12.50 mg GAE/g between 8 and 12 h, the principal component analysis confirmed that the flora, altitude, and climate of the propolis location influenced the content of bioactive compounds, antioxidant capacity, and other properties studied. The nanoencapsulate from the district of Huancaray was the one with the best results, allowing its future use as a natural ingredient in functional foods. Nevertheless, technological, sensory, and economic studies should still be carried out.

Poly(Lactic Acid) Block Copolymers with Poly(Hexylene Succinate) as Microparticles for Long-Acting Injectables of Risperidone Drug

In the present work, Risperidone microparticles from poly(lactic acid)/poly(hexylene succinate) (PLA-b-PHSu) block copolymers in different ratios, 95/05, 90/10 and 80/20 w/w, were examined as long-acting injectable formulations. Nuclear magnetic resonance (NMR) was used to verify the successful synthesis of copolymers. Enzymatic hydrolysis showed an increase in weight loss as the content of PHSu increased, while the cytotoxicity studies confirmed the biocompatibility of the copolymers. The polyesters were further used to encapsulate Risperidone by spray drying. The drug-loaded microparticles were studied by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray diffraction (XRD). SEM microphotographs confirmed that spherically shaped microparticles were prepared with sizes about 5-12 μm, while XRD and differential scanning calorimetry (DSC) studies evidenced that Risperidone was encapsulated in amorphous form. The drug loading and the entrapment efficiency of Risperidone were studied as well as the in vitro release from the prepared microparticles. As the content of PHSu increased, a higher release of Risperidone was observed, with PLA-b-PHSu 80/20 w/w succeeding to release 100% of RIS within 12 days. According to theoretical modeling, the kinetics of RIS release from PLA-b-PHSu microparticles is complex, governed by both diffusion and polymer erosion.

Levonorgestrel loaded biodegradable microparticles for injectable contraception: Preparation, characterization and modelling of drug release

The integration of mechanistic modeling and machine learning facilitates the understanding and engineering of drug release from controlled release systems. Here, we present hybrid models to predict the effect of drug loading on levonorgestrel release from spray-dried poly(L-lactic acid) microparticles. We developed three Monte Carlo methods that differ in the consideration of polymer's degradability and crystallinity, to simulate drug release from the matrices using the Python programming language. To build each method, we utilized data from the characterization of the particles, such as the actual drug content (ranges from 6% to 52%), size (Dv(50) ∼ 5 μm), and polymer crystallinity (ranges from 0% to 15%). We trained each method using drug release data from particles of 4 batches and derived appropriate machine learning models through regression analysis. Results indicate the contribution of drug diffusion and polymer degradation to drug release for particles of lower drug content (<20 %w/w). At higher drug loadings, particles encountered a combination of burst and diffusional release. We validated the predictive powers of the machine learning models by testing them against experimental data. This paper specifically highlights the power of hybrid modeling to engineer drug release for long-term contraception.

Preparation and Evaluation of Mucus-Penetrating Inhalable Microparticles of Tiotropium Bromide Containing Sodium Glycocholate

This study aimed to prepare mucus-penetrating inhalable microparticles for dry powder inhalers and to evaluate their applicability in an asthma-induced rat model. Microparticles were prepared from water solutions containing tiotropium bromide, L-leucine, and sodium glycocholate (NaGc) as permeation enhancers using the spray drying method. Four formulations (SDL1, SDL2, SDL3, and SDL4) were used, depending on the various NaGc concentrations. Tiotropium microparticles were characterized by standard methods. Additionally, an asthma-induced rat model was used to confirm the effects of the formulations on lung function. Tiotropium microparticles with NaGc resulted in formulations with a more corrugated morphology and smaller particle size distribution than those without NaGc. SDL 1 had a rough surface with irregular morphology, and SDL 2, 3, and 4 had a corrugated morphology. All SDL formulations had an aerodynamic size of <3 µm. The microparticles with a corrugated morphology aerosolized better than SDL1 microparticles. The apparent permeability coefficient (Papp) values of SDL3 and SDL4 were significantly higher than those for raw tiotropium. In an in vivo study using an asthma-induced rat model, the specific airway resistance (Sraw), airway wall thickness, and mean alveolus size recovered to those of the negative control group in the SDL4 formulation.

Iontophoretic ocular delivery of latanoprost-loaded nanoparticles via skin-attached electrodes

Prolonged drug efficacy to reduce the number of administrations is a key factor in the successful treatment of glaucoma through topical drug delivery to the eye. Therefore, we propose a new strategy for iontophoretic ocular delivery of drug-loaded nanoparticles. Considering safety and convenience, our strategy is involved with topical administration of the drug-loaded nanoparticles followed by their permeation into the eye tissues via noninvasive iontophoresis, using the skin-attached electrodes. Thus, those nanoparticles stayed longer in the eye, and during this period, the drug was released in a sustained manner, thereby prolonging drug exposure even with one-time treatment. The nanoparticles were made of poly(lactic-co-glycolic acid) (PLGA), which were loaded with a glaucoma drug, latanoprost. We varied the size of the nanoparticles at 100, 200, 300, and 500 nm and sought to find the optimum size under the fixed conditions for iontophoresis proposed in this work (4 mA; 30 min). Even with iontophoresis through the skin-attached electrodes, the nanoparticles were indeed deposited in the eye tissues, where with an increase in particle size, drug release was more sustained, but fewer particles could permeate into the eye tissues. Because of these two competing factors, iontophoretic delivery of the 300-nm particles exhibited the most prolonged drug efficacy in vivo for more than 7 days, and showed an approximately 23-fold increase in drug efficacy compared with that of Xalatan®, a commercially available eye drop of latanoprost developed for once-a-day administration every day. STATEMENT OF SIGNIFICANCE: To treat glaucoma, conventional eye drops are often prescribed; however, they often require multiple daily administrations due to rapid preocular clearance. To resolve this, we suggest a noninvasive iontophoretic ocular delivery of latanoprost-loaded PLGA nanoparticles using the skin-attached electrodes. Even with iontophoresis via the skin-attached electrodes, the nanoparticles can indeed be deposited into the eye tissues. However, with an increase in particle size, fewer particles can permeate into the eye tissues, although drug release is more sustained. Therefore, the particles with a size of 300 nm show the optimal in vivo delivery profile in this work, where the drug efficacy can be extended for more than 7 days with a single administration.

PLGA-Based Composites for Various Biomedical Applications

Polymeric materials have been extensively explored in the field of nanomedicine; within them, poly lactic-co-glycolic acid (PLGA) holds a prominent position in micro- and nanotechnology due to its biocompatibility and controllable biodegradability. In this review we focus on the combination of PLGA with different inorganic nanomaterials in the form of nanocomposites to overcome the polymer’s limitations and extend its field of applications. We discuss their physicochemical properties and a variety of well-established synthesis methods for the preparation of different PLGA-based materials. Recent progress in the design and biomedical applications of PLGA-based materials are thoroughly discussed to provide a framework for future research.

Inhalation potential of N-Acetylcysteine loaded PLGA nanoparticles for the management of tuberculosis: In vitro lung deposition and efficacy studies

Several studies have stated that mucus is a critical hurdle for drug delivery to the mucosal tissues. As a result, Polymeric nanoparticles that can overcome mucus barriers are gaining popularity for controlled drug delivery into intra-macrophages to attain high intracellular drug concentration. The present study was aimed to fabricate inhalable N-acetylcysteine (NAC) modified PLGA mucus penetrating particles using the double emulsion method (w/o/w) for target delivery to alveolar macrophages and minimize the dose-related adverse effects, efficiently encapsulate hydrophilic drug, sustain the release profile and prolong the retention time for the management of tuberculosis. Among the numerous formulations, the drug/polymer ratio of 1:10 with 0.50% PVA concentration and sonication time for 2 ​min ​s was chosen for further research. The formulated nanoparticles had a mean particle size of 307.50 ​± ​9.54 ​nm, PDI was 0.136 ​± ​0.02, zeta potential about -11.3 ​± ​0.4 ​mV, decent entrapment efficiency (55.46 ​± ​2.40%), drug loading (9.05 ​± ​0.22%), and excellent flowability. FTIR confirmed that NAC and PLGA were compatible with each other. SEM graphs elucidated that the nanoparticles were spherically shaped with a slightly rough surface whereas TEM analysis ensured the nanometer size nanoparticles and coating of lipid over NPs surface. PXRD spectrum concluded the transformation of the drug from crystalline to amorphous state in the formulation. In vitro release pattern was biphasic started with burst release (64.67 ​± ​1.53% within 12hrs) followed by sustained release over 48hrs thus enabling the prolonged replenishing of NAC. In vitro lung deposition study pronounced that coated NAC-PLGA-MPPs showed favorable results in terms of emitted dose (86.67 ​± ​2.52%), MMAD value (2.57 ​± ​0.12 ​μm), GSD value (1.55 ​± ​0.11 ​μm), and FPF of 62.67 ​± ​2.08% for the deposition and targeting the lungs. Finally, in vitro efficacy studies demonstrated that NAC-PLGA-MPPs presented more prominent antibacterial activity against MTB H37Rv strain as compared to NAC. Hence, PLGA based particles could be a better strategy to deliver the NAC for lung targeting.

One-Pot Preparation of Hydrophilic Polylactide Porous Scaffolds by Using Safe Solvent and Choline Taurinate Ionic Liquid

Polylactides (PLAs) are a class of polymers that are very appealing in biomedical applications due to their degradability in nontoxic products, tunable structural, and mechanical properties. However, they have some drawbacks related to their high hydrophobicity, lack of functional groups able to graft bioactive molecules, and solubility in unsafe solvents. To circumvent these shortcomings, porous scaffolds for tissue engineering were prepared by vigorously mixing a solution of isotactic and atactic PLA in nontoxic ethyl acetate at 70 °C with a water solution of choline taurinate. The partial aminolysis of the polymer ester bonds by taurine –NH₂ brought about the formation of PLA oligomers with surfactant activity that stabilized the water-in-oil emulsion. Upon drying, a negligible shrinking occurred, and mechanically stable porous scaffolds were obtained. By varying the polymer composition and choline taurinate concentration, it was possible to modulate the pore dimensions (30–50 µm) and mechanical properties (Young’s moduli: 1–6 MPa) of the samples. Furthermore, the grafted choline taurinate made the surface of the PLA films hydrophilic, as observed by contact angle measurements (advancing contact angle: 76°; receding contact angle: 40°–13°). The preparation method was very simple because it was based on a one-pot mild reaction that did not require an additional purification step, as all the employed chemicals were nontoxic.

Sodium Caseinate and Acetylated Mung Bean Starch for the Encapsulation of Lutein: Enhanced Solubility and Stability of Lutein

Lutein is a kind of vital carotenoid with high safety and significant advantages in biological functions. However, poor water solubility and stability of lutein have limited its application. This study selected different weight ratios of sodium caseinate to acetylated mung bean starch (10:0, 9:1, 7:3, 5:5, 3:7, 1:9, and 0:10) to prepare lutein emulsions, and the microcapsules were produced by spray drying technology. The microstructure, physicochemical properties, and storage stability of microcapsules were investigated. The results show that the emulsion systems were typical non-Newtonian fluids. Lutein microcapsules were light yellow fine powder with smooth and relatively complete particle surface. The increase of sodium caseinate content led to the enhanced emulsion effect of the emulsion and the yield and solubility of microcapsules increased, and wettability and the average particle size became smaller. The encapsulation efficiency of lutein microcapsules ranged from 69.72% to 89.44%. The thermal characteristics analysis showed that the endothermic transition of lutein microcapsules occurred at about 125 °C. The microcapsules with sodium caseinate as single wall material had the worst stability. Thus, it provides a reference for expanding the application of lutein in food, biological, pharmaceutical, and other industries and improving the stability and water dispersion of other lipid-soluble active ingredients.

Redefining the importance of polylactide-co-glycolide acid (PLGA) in drug delivery

The limitations of non-biodegradable polymers have paved the way for biodegradable polymers in the pharmaceutical and biomedical sciences over the years. Poly (lactic-co-glycolic acid) (PLGA), also known as 'Smart polymer', is one of the most successfully developed biodegradable polymers due to its favorable properties, such as biodegradability, biocompatibility, controllable drug release profile, and ability to alter surface with targeting agents for diagnosis and treatment. The release behavior of drugs from PLGA delivery devices is influenced by the physicochemical properties of PLGA. In this review, the current state of the art of PLGA, its synthesis, physicochemical properties, and degradation are discussed to enunciate the boundaries of future research in terms of its applicability with the optimized design in today's modern age. The fundamental objective of this review is to highlight the significance of PLGA as a polymer in the field of cancer, cardiovascular diseases, neurological disorders, dentistry, orthopedics, vaccine therapy, theranostics and lastly emerging epidemic diseases like COVID-19. Furthermore, the coverage of recent PLGA-based drug delivery systems including nanosystems, microsystems, scaffolds, hydrogels, etc. has been summarized. Overall, this review aims to disseminate the PLGA-driven revolution of the drug delivery arena in the pharmaceutical and biomedical industry and bridge the lacunae between material research, preclinical experimentation, and clinical reality.

Physico-Chemical, In Vitro and Ex Vivo Characterization of Meloxicam Potassium-Cyclodextrin Nanospheres

Nasal drug delivery has many beneficial properties, such as avoiding the first pass metabolism and rapid onset of action. However, the limited residence time on the mucosa and limited absorption of certain molecules make the use of various excipients necessary to achieve high bioavailability. The application of mucoadhesive polymers can increase the contact time with the nasal mucosa, and permeation enhancers can enhance the absorption of the drug. We aimed to produce nanoparticles containing meloxicam potassium (MEL-P) by spray drying intended for nasal application. Various cyclodextrins (hydroxypropyl-β-cyclodextrin, α-cyclodextrin) and biocompatible polymers (hyaluronic acid, poly(vinylalcohol)) were used as excipients to increase the permeation of the drug and to prepare mucoadhesive products. Physico-chemical, in vitro and ex vivo biopharmaceutical characterization of the formulations were performed. As a result of spray drying, mucoadhesive nanospheres (average particle size <1 µm) were prepared which contained amorphous MEL-P. Cyclodextrin-MEL-P complexes were formed and the applied excipients increased the in vitro and ex vivo permeability of MEL-P. The highest amount of MEL-P permeated from the α-cyclodextrin-based poly(vinylalcohol)-containing samples in vitro (209 μg/cm²) and ex vivo (1.47 μg/mm²) as well. After further optimization, the resulting formulations may be promising for eliciting a rapid analgesic effect through the nasal route.

Stabilization by Nano Spray Dryer of Pioglitazone Polymeric Nanosystems: Development, In Vivo, Ex Vivo and Synchrotron Analysis

Pioglitazone-loaded PLGA-PEG nanoparticles (NPs) were stabilized by the spray drying technique as an alternative to the treatment of ocular inflammatory disorders. Pioglitazone-NPs were developed and characterized physiochemically. Interaction studies, biopharmaceutical behavior, ex vivo corneal and scleral permeation, and in vivo bioavailability evaluations were conducted. Fibrillar diameter and interfibrillar corneal spacing of collagen was analyzed by synchrotron X-ray scattering techniques and stability studies at 4 °C and was carried out before and after the spray drying process. NPs showed physicochemical characteristics suitable for ocular administration. The release was sustained up to 46 h after drying; ex vivo corneal and scleral permeation profiles of pioglitazone-NPs before and after drying demonstrated higher retention and permeation through cornea than sclera. These results were correlated with an in vivo bioavailability study. Small-angle X-ray scattering (SAXS) analysis did not show a significant difference in the organization of the corneal collagen after the treatment with pioglitazone-NPs before and after the drying process, regarding the negative control. The stabilization process by Nano Spray Dryer B-90 was shown to be useful in preserving the activity of pioglitazone inside the NPs, maintaining their physicochemical characteristics, in vivo bioavailability, and non-damage to corneal collagen function after SAXS analysis was observed.

Nano Spray-Dried Drugs for Oral Administration: A Review

Spray drying is an important technology that is fast, simple, reproducible, and scalable. It has a wide application range, that is, in food, chemicals, and encapsulation of pharmaceuticals. The technology can be divided into conventional spray drying and nano spray drying. The key advantage of nano spray drying is the production of drug-loaded nanosized particles for various drug delivery applications. The recent developments in nano spray dryer technology and the market launch of the Nano Spray Dryer B-90 by Büchi Labortechnik AG in 2009 enabled the production of submicron spray-dried particles. This review focuses on nanosized drug delivery systems intended for oral administration produced by nano spray drying. First, the nano spray drying concept, the basic technologies implemented in the equipment, and the effects of the various process parameters on the final dry submicron powder properties are presented. Then, the topics of new formulation strategies of oral drugs are highlighted with examples that have entered the research literature in recent years. Next, the subjects of direct conversion of poorly water-soluble drugs, encapsulation of drugs, and drying of preformed nanoparticles are considered. Finally, topics such as morphology, particle size, size distribution, surface analysis, bioavailability, drug release, release kinetics, and solid-state characterization (by differential scanning calorimetry, X-ray diffraction, Fourier transform infrared spectroscopy, nuclear magnetic resonance) of oral drug delivery systems produced by nano spray drying are discussed. The review attempts to provide a comprehensive knowledge base with current literature and foresight to researchers working in the field of pharmaceutical technology and nanotechnology and especially in the field of nano spray drying.

Inhalable nanoparticles delivery targeting alveolar macrophages for the treatment of pulmonary tuberculosis

Pulmonary tuberculosis is a highly prevalent respiratory disease that affects approximately a quarter of the world's population. The drug treatment protocol for tuberculosis is complex because the Mycobacterium tuberculosis (M. tuberculosis) invades macrophages and begins to infect. Thus treatment usually includes combination therapy with several drugs such as rifampicin, pyrazinamide, isoniazid, and ethambutol over a long dosing period. Therefore, drug-delivery technologies have been developed to improve patient compliance with medication, reduce adverse effects, and increase effectiveness of the treatment. In the present review, we have discussed recent inhalable nanopharmaceutical systems for the treatment of pulmonary tuberculosis and investigated their design and effectiveness. We examined the underlying processes and characteristics of spray-drying technology and studied the formulation of a dry carrier using spray-drying method. Moreover, we reviewed various research articles on pulmonary delivery of nanoparticles using these carriers, and studied their alveolar macrophage targeting ability and therapeutic effects. Further, we appraised the effectiveness of nanoparticle inhalation therapy for the treatment of pulmonary tuberculosis and its potential as a treatment strategy for lung diseases.

Polymeric nanocapsules: A review on design and production methods for pharmaceutical purpose

Polymeric nanocapsules have extensive application potential in medical, biological, and pharmaceutical fields, and, therefore, much research has been dedicated to their production. Indeed, production protocols and the materials used are decisive for obtaining the desired nanocapsules characteristics and biological performance. In addition to that, several technological strategies have been developed in the last decade to improve processing techniques and form more valuable nanocapsules. This review provides a guide to current methods for developing polymeric nanocapsules, reporting aspects to be considered when choosing appropriate materials, and discussing different ways to produce nanocapsules for superior performances.

Translating the fabrication of protein-loaded poly(lactic-co-glycolic acid) nanoparticles from bench to scale-independent production using microfluidics

In the formulation of nanoparticles, poly(lactic-co-glycolic acid) (PLGA) is commonly employed due to its Food and Drug Administration and European Medicines Agency approval for human use, its ability to encapsulate a variety of moieties, its biocompatibility and biodegradability and its ability to offer a range of controlled release profiles. Common methods for the production of PLGA particles often adopt harsh solvents, surfactants/stabilisers and in general are multi-step and time-consuming processes. This limits the translation of these drug delivery systems from bench to bedside. To address this, we have applied microfluidic processes to develop a scale-independent platform for the manufacture, purification and monitoring of nanoparticles. Thereby, the influence of various microfluidic parameters on the physicochemical characteristics of the empty and the protein-loaded PLGA particles was evaluated in combination with the copolymer employed (PLGA 85:15, 75:25 or 50:50) and the type of protein loaded. Using this rapid production process, emulsifying/stabilising agents (such as polyvinyl alcohol) are not required. We also incorporate in-line purification systems and at-line particle size monitoring. Our results demonstrate the microfluidic control parameters that can be adopted to control particle size and the impact of PLGA copolymer type on the characteristics of the produced particles. With these nanoparticles, protein encapsulation efficiency varies from 8 to 50% and is controlled by the copolymer of choice and the production parameters employed; higher flow rates, combined with medium flow rate ratios (3:1), should be adopted to promote higher protein loading (% wt/wt). In conclusion, herein, we outline the process controls for the fabrication of PLGA polymeric nanoparticles incorporating proteins in a rapid and scalable manufacturing process. Scale-independent production of polymer nanoparticles.

A Comparison of Microfluidic-Jet Spray Drying, Two-Fluid Nozzle Spray Drying, and Freeze-Drying for Co-Encapsulating β-Carotene, Lutein, Zeaxanthin, and Fish Oil

Various microencapsulation techniques can result in significant differences in the properties of dried microcapsules. Microencapsulation is an effective approach to improve fish oil properties, including oxidisability and unpleasant flavour. In this study, β-carotene, lutein, zeaxanthin, and fish oil were co-encapsulated by microfluidic-jet spray drying (MFJSD), two-fluid nozzle spray drying (SD), and freeze-drying (FD), respectively. The aim of the current study is to understand the effect of different drying techniques on microcapsule properties. Whey protein isolate (WPI) and octenylsuccinic anhydride (OSA) modified starch were used as wall matrices in this study for encapsulating carotenoids and fish oil due to their strong emulsifying properties. Results showed the MFJSD microcapsules presented uniform particle size and regular morphological characteristics, while the SD and FD microcapsules presented a large distribution of particle size and irregular morphological characteristics. Compared to the SD and FD microcapsules, the MFJSD microcapsules possessed higher microencapsulation efficiency (94.0–95.1%), higher tapped density (0.373–0.652 g/cm³), and higher flowability (the Carr index of 16.0–30.0%). After a 4-week storage, the SD microcapsules showed the lower retention of carotenoids, as well as ω-3 LC-PUFAs than the FD and MFJSD microcapsules. After in vitro digestion trial, the differences in the digestion behaviours of the microcapsules mainly resulted from the different wall materials, but independent of drying methods. This study has provided an alternative way of delivering visual-beneficial compounds via a novel drying method, which is fundamentally essential in both areas of microencapsulation application and functional food development.

Single step nanospray drying preparation technique of gabapentin-loaded nanoparticles-mediated brain delivery for effective treatment of PTZ-induced seizures

In the present study, gabapentin (GBP)-loaded chitosan nanosized particles were fabricated applying the nanospray drying technique. Different preparation parameters (spray mesh diameter, chitosan concentration and presence of D-α-Tocopherol polyethylene glycol 1000 succinate (TPGS) were studied while fixing other parameters (spraying rate, inlet temperature and gas flow rate). An optimized formulation with a particle size 107 ± 13 nm was obtained upon spraying 0.1% (w/v) chitosan solution containing 0.05% (w/v) of TPGS utilizing the small nozzle (4 μm spray mesh hole size). Drug entrapment efficiency and yield were as high as 95% and 83%, respectively. A 98.1 ± 6.1% (w/w) cumulative drug release was recorded after 2 h. Confocal laser scanning microscopy showed higher fluorescent dye penetration into brain tissue following intranasal administration of Rhodamine B labeled spray dried chitosan nanoparticles (NPs) as compared to Rhodamine B solution. Pentylenetetrazole (PTZ) was used to induce convulsions in rats through elevating seizure stages, releasing neuroinflammatory mediators and reducing excitatory amino acid transporter 2 (EAAT 2) and γ-aminobutyric acid (GABA) brain contents. Nanospray dried GBP-loaded chitosan NPs reduced seizure score, neuroinflammation; TNF-α and TGF-β, elevated EAAT 2 and GABA as well as decreased degeneration in pyramidal neurons compared to marketed product Conventin® capsules. Thus, it can be concluded from the aforementioned data that nanospray dried GBP-loaded chitosan NPs could comprise an appropriate treatment of epilepsy.

The effect of ethanol on the habit and in vitro aerodynamic results of dry powder inhalation formulations containing ciprofloxacin hydrochloride

In the case of dry powder inhalation systems (DPIs), the development of carrier-free formulations has gained increased attention. Thereby, spray-drying is a promising technology and is widely used to produce carrier-free DPIs. Numerous works have been published about the co-spray-drying of active ingredients with various solid excipients and their effect on the physicochemical characteristics and aerodynamic properties of the formulations. However, only a few studies have been reported about the role of the solvents used in the stock solutions of spray-dried formulations. In the present work, DPI microcomposites containing ciprofloxacin hydrochloride were prepared by spray-drying in the presence of different ethanol concentrations. The work expresses the roughness, depth and width of the dimples for particle size as a novel calculation possibility, and as a correlation between the MMAD/D_0.5 ratio and correlating it with cohesion work, these new terms and correlations have not been published – to the best of our knowledge – which has resulted in gap-filling findings. As a result, different proportions of solvent mixtures could be interpreted and placed in a new perspective, in which the influence of different concentrations of ethanol on the habit of the DPI formulations, and thus on in vitro aerodynamic results. Based on these, it became clear why we obtained the best in vitro aerodynamic results for DPI formulation containing 30% ethanol in the stock solution.

PLGA Nanoparticle-Based Formulations to Cross the Blood-Brain Barrier for Drug Delivery: From R&D to cGMP

The blood–brain barrier (BBB) is a natural obstacle for drug delivery into the human brain, hindering treatment of central nervous system (CNS) disorders such as acute ischemic stroke, brain tumors, and human immunodeficiency virus (HIV)-1-associated neurocognitive disorders. Poly(lactic-co-glycolic acid) (PLGA) is a biocompatible polymer that is used in Food and Drug Administration (FDA)-approved pharmaceutical products and medical devices. PLGA nanoparticles (NPs) have been reported to improve drug penetration across the BBB both in vitro and in vivo. Poly(ethylene glycol) (PEG), poly(vinyl alcohol) (PVA), and poloxamer (Pluronic) are widely used as excipients to further improve the stability and effectiveness of PLGA formulations. Peptides and other linkers can be attached on the surface of PLGA to provide targeting delivery. With the newly published guidance from the FDA and the progress of current Good Manufacturing Practice (cGMP) technologies, manufacturing PLGA NP-based drug products can be achieved with higher efficiency, larger quantity, and better quality. The translation from bench to bed is feasible with proper research, concurrent development, quality control, and regulatory assurance.

Rosemary oil nano-emulsion potentiates the apoptotic effect of mitomycin C on cancer cells in vitro

Purpose: To formulate nano-emulsified rosemary oil (REO/NE) and determine its effect on the anticancer agent, mitomycin C (MC) when used as a carrier for the drug.

Methods: The droplet size of REO/NE was markedly enlarged when mixed with MC. The cytotoxicity of the formulations on HeLa and MCF-7 cells was determined using MTT assay. The combination index (CI) values were estimated with CompuSyn software, while apoptosis was determined using DAPI fluorescent dye.

Results: Treatment of MCF-7 cells and HeLa cells with REO/NE (1% v:v and 1.33% v:v, respectively) reduced the IC50 of MC 33 and 15 folds, respectively. Under fluorescent microscopy, cells treated with REO/NE+MC had more marked reduction of the nuclear area than MC-treated cells.

Conclusion: These results indicate that REO/NE is an efficient carrier for MC since it enhanced MC delivery and increased its effect on the cells through the induction of apoptosis at low concentrations of MC.

Enhanced Oral Bioavailability of Resveratrol by Using Neutralized Eudragit E Solid Dispersion Prepared via Spray Drying

In this study, we designed amorphous solid dispersions based on Eudragit E/HCl (neutralized Eudragit E using hydrochloric acid) to maximize the dissolution of trans-resveratrol. Solid-state characterization of amorphous solid dispersions of trans-resveratrol was performed using powder X-ray diffraction, scanning electron microscopy, and particle size measurements. In addition, an in vitro dissolution study and an in vivo pharmacokinetic study in rats were carried out. Among the tested polymers, Eudragit E/HCl was the most effective solid dispersion for the solubilization of trans-resveratrol. Eudragit E/HCl significantly inhibited the precipitation of trans-resveratrol in a pH 1.2 dissolution medium in a dose-dependent manner. The amorphous Eudragit E/HCl solid dispersion at a trans-resveratrol/polymer ratio of 10/90 exhibited a high degree of supersaturation without trans-resveratrol precipitation for at least 48 h by the formation of Eudragit E/HCl micelles. In rats, the absolute oral bioavailability (F%) of trans-resveratrol from Eudragit E/HCl solid dispersion (10/90) was estimated to be 40%. Therefore, trans-resveratrol-loaded Eudragit E/HCl solid dispersions prepared by spray drying offer a promising formulation strategy with high oral bioavailability for developing high-quality health supplements, nutraceutical, and pharmaceutical products.

Polymeric Nanoparticle-Based Vaccine Adjuvants and Delivery Vehicles

As vaccine formulations have progressed from including live or attenuated strains of pathogenic components for enhanced safety, developing new adjuvants to more effectively generate adaptive immune responses has become necessary. In this context, polymeric nanoparticles have emerged as a promising platform with multiple advantages, including the dual capability of adjuvant and delivery vehicle, administration via multiple routes, induction of rapid and long-lived immunity, greater shelf-life at elevated temperatures, and enhanced patient compliance. This comprehensive review describes advances in nanoparticle-based vaccines (i.e., nanovaccines) with a particular focus on polymeric particles as adjuvants and delivery vehicles. Examples of the nanovaccine approach in respiratory infections, biodefense, and cancer are discussed.

Albumin and functionalized albumin nanoparticles: production strategies, characterization, and target indications

The inherent properties of albumin facilitate its effective use as a raw material to prepare a nanosized drug delivery vehicles. Because of the enhanced surface area, biocompatibility, and extended half-life of albumin nanoparticles, a number of drugs have been incorporated in albumin matrices in recent years. Furthermore, its ability to be conjugated to various receptor ligands makes albumin an ideal candidate for the increased delivery of drugs to specific sites. The present review provides an in-depth discussion of production strategies for the preparation of albumin and conjugated albumin nanoparticles and for the targeting of these formulations to specific organs and cancer cells. This review also provides insights into drug loading, release patterns, and cytotoxicity of various drug-loaded albumin nanoparticles.

Poly (Lactic-co-Glycolic Acid) Nanoparticles and Nanoliposomes for Protein Delivery in Targeted Therapy: A Comparative In Vitro Study

Over the previous years, the design, development, and potential application of nanocarriers in the medical field have been intensively studied for their ability to preserve drug properties, especially their pharmacological activity, and to improve their bioavailability. This work is a comparative study between two different types of nanocarriers, poly (lactic-co-glycolic acid)-based nanoparticles and phosphatidylcholine-based nanoliposomes, both prepared for the encapsulation of bovine serum albumin as a model protein. Polymeric nanoparticles were produced using the double emulsion water-oil-water evaporation method, whereas nanoliposomes were obtained by the thin-film hydration method. Both nanocarriers were characterized by morphological analysis, particle mean size, particle size distribution, and protein entrapment efficiency. Invitro release studies were performed for 12 days at 37 °C. In order to explore a possible application of these nanocarriers for a targeted therapy in the cardiovascular field, hemolytic activity and biocompatibility, in terms of cell viability, were performed by using human red blood cells and EA.hy926 human endothelial cell line, respectively.

An Overview on Spray-Drying of Protein-Loaded Polymeric Nanoparticles for Dry Powder Inhalation

The delivery of therapeutic proteins remains a challenge, despite recent technological advances. While the delivery of proteins to the lungs is the gold standard for topical and systemic therapy through the lungs, the issue still exists. While pulmonary delivery is highly attractive due to its non-invasive nature, large surface area, possibility of topical and systemic administration, and rapid absorption circumventing the first-pass effect, the absorption of therapeutic proteins is still ineffective, largely due to the immunological and physicochemical barriers of the lungs. Most studies using spray-drying for the nanoencapsulation of drugs focus on the delivery of conventional drugs, which are less susceptible to bioactivity loss, compared to proteins. Herein, the development of polymeric nanoparticles by spray-drying for the delivery of therapeutic proteins is reviewed with an emphasis on its advantages and challenges, and the techniques to evaluate their in vitro and in vivo performance. The protein stability within the carrier and the features of the carrier are properly addressed.

Shear-Induced Heteroaggregation of Oppositely Charged Colloidal Particles

This paper investigates numerically the shear-induced aggregation of mixed populations of colloidal particles leading to the formation of clusters. Suspensions with different amounts of positively and negatively charged colloidal particles are simulated. To resolve the aggregation kinetics and structural properties of the formed clusters, we resort to a mixed deterministic-stochastic simulation method. The method is built on a combination of a Monte Carlo algorithm to sample a statistically expected sequence of encounter events between the suspended particles and a discrete element method built in the framework of Stokesian dynamics to simulate the encounters in a fully predictive manner. Results reveal a strong influence of the composition of the population on both the aggregation kinetics and the aggregate structure. In particular, we observe a size-stabilization phenomenon taking place in the suspension when the relative concentration of the majority particles lies in the range 80-85%; i.e., starting from primary particles, after a short growth period, we observed a cessation of aggregation. Inspection of the aggregate morphology shows that the formed clusters are composed of few minority particles placed in the inner region, while the aggregate surface is covered by majority particles, acting to provide a shielding effect against further growth.

The Effect of Particle Size and Surface Roughness of Spray-Dried Bosentan Microparticles on Aerodynamic Performance for Dry Powder Inhalation

The purpose of this study was to prepare spray dried bosentan microparticles for dry powder inhaler and to characterize its physicochemical and aerodynamic properties. The microparticles were prepared from ethanol/water solutions containing bosentan using spray dryer. Three types of formulations (SD60, SD80, and SD100) depending on the various ethanol concentrations (60%, 80%, and 100%, respectively) were used. Bosentan microparticle formulations were characterized by scanning electron microscopy, powder X-ray diffraction, laser diffraction particle sizing, differential scanning calorimetry, Fourier-transform infrared spectroscopy, dissolution test, and in vitro aerodynamic performance using Andersen cascade impactor^™ (ACI) system. In addition, particle image velocimetry (PIV) system was used for directly confirming the actual movement of the aerosolized particles. Bosentan microparticles resulted in formulations with various shapes, surface morphology, and particle size distributions. SD100 was a smooth surface with spherical morphology, SD80 was a rough surfaced with spherical morphology and SD60 was a rough surfaced with corrugated morphology. SD100, SD80, and SD60 showed significantly high drug release up to 1 h compared with raw bosentan. The aerodynamic size of SD80 and SD60 was 1.27 µm and SD100 was 6.95 µm. The microparticles with smaller particle size and a rough surface aerosolized better (%FPF: 63.07 ± 2.39 and 68.27 ± 8.99 for SD60 and SD80, respectively) than larger particle size and smooth surface microparticle (%FPF: 22.64 ± 11.50 for SD100).

Preparation and Properties of Stereocomplex of Poly(lactic acid) and Its Amphiphilic Copolymers Containing Glucose Groups

The stereocomplex of poly(lactic acid) containing glucose groups (sc-PLAG) was prepared by solution blending from equal amounts of poly(l-lactic acid) (PLLA) and poly(d-lactic acid-co-glucose) (PDLAG), which were synthesized from l- and d-lactic acid and glucose by melt polycondensation. The methods, including 1H nuclear magnetic resonance spectroscopy (1H NMR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), polarizing microscope (POM), scanning electron microscope (SEM), transmission electron microscope (TEM), and contact angle were used to determine the effects of the stereocomplexation of enantiomeric poly(lactic acid) (PLA) units, the amphiphilicity due to glucose residues and lactic acid units, and the interaction of glucose residues with lactic units on the crystallization performance, hydrophilicity, thermal stability, and morphology of samples. The results showed PDLAG was multi-armed, and partial OH groups of glucose residues in PDLAG might remain unreacted. The molecular weight (Mw), dispersity (Ɖ), and glucose proportion in the chain of PDLAG thereby had significant effects on sc-PLAG. There were the stereocomplexation of enantiomeric lactic units and the amphiphilic self-assembly of PDLAG in sc-PLAG, which resulted in glucose groups mainly in the surface phase and lactic units in the bulk phase. The sc-PLAG only possessed the stereocomplex crystal owing to the interaction between nearly equimolar of l-lactic units of PLLA and d-lactic units of PDLAG, and had no homo-crystallites of l- or d-lactic units, which improved the melting temperature (Tm) of sc-PLAG about 50 °C higher than that of PLLA. Glucose groups in sc-PLAG played an important role by forming heterogeneous nucleation, promoting amphiphilic self-assembly, and affecting the ordered arrangement of lactic units. The glass transition temperature (Tg), the melting temperature (Tm), crystallinity, crystallization rate, and water absorption of sc-PLAG showed similar changes with the increased glucose content in feeding. All these parameters increased at first, and the maximum appeared as glucose content in feeding about 2%, such as the maximum crystallinity of 48.8% and the maximum water absorption ratio being 11.7%. When glucose content in feeding continued increasing, all these performances showed a downward trend due to the decrease of arrangement regularity of lactic acid chains caused by glucose groups. Moreover, the contact angle of sc-PLAG decreased gradually with the increased glucose content in feeding to obtain the minimum 77.5° as the glucose content in feeding being 5%, while that of PLLA was 85.0°. The sc-PLAG possessed a regular microsphere structure, and its microspheres with a diameter of about 200 nm could be observed. In conclusion, sc-PLAG containing proper glucose amount could effectively enhance the crystallinity, hydrophilicity, and thermal stability of PLA material, which is useful for drug delivery, a scaffold for tissue engineering, and other applications of biomedicine.

A smart approach to enable preclinical studies in pharmaceutical industry: PLGA-based extended release formulation platform for subcutaneous applications

Objective: Validation of a prospective new therapeutic concept in a proof of concept study is costly and time-consuming. In particular, pharmacologically active tool compounds often lack suitable pharmacokinetic (PK) properties for subsequent studies. The current work describes a PLGA-based formulation platform, encapsulating different preclinical research compounds into extended release microparticles, to optimize their PK properties after subcutaneous administration.Significance: Developing a PLGA-based formulation platform offers the advantage of enabling early proof of concept studies in pharmaceutical research for a variety of preclinical compounds by providing a tailor-made PK profile.Methods: Different model compounds were encapsulated into PLGA microparticles, utilizing emulsification solvent evaporation or spray drying techniques. Formulations aiming different release rates were manufactured and characterized. Optimized formulations were assessed in in vivo studies to determine their PK properties, with the mean residence time (MRT) as one key PK parameter.Results: Utilizing both manufacturing methods, tested tool compounds were encapsulated successfully, with a drug load between 5% and 40% w/w, and an extended release time up to 250 h. In the following PK studies, the MRT was extended by a factor of 90, resulting in prolonged coverage of the required target through level. This approach was confirmed to be equally successful for additional internal compounds, verifying a general applicability of the platform.Conclusion: For different active pharmaceutical ingredients (API), an optimized, tailor-made PK profile was obtained utilizing the described formulation platform. This approach is applicable for a variety of pharmacologically active tool compounds, reducing timelines and costs in preclinical research.

Revolutionizing technologies of nanomicelles for combinatorial anticancer drug delivery

Insufficient efficacy of current single drug therapy of cancers have led to the advancement of combination drug-loaded formulations. Specifically, polymeric micelles have been focused on as efficient injectable vehicles for the delivery of several anticancer drugs simultaneously to cancer cells. These nano delivery systems have evolved with advancements in the area of nanotechnology. The current review presents a summary of the past events that have led to the procession of nanomicelles and novel nanotechnologies for combinatorial drug delivery. It also focuses on the advantages, disadvantages, and considerations for the design of nanotechnologies for combinatorial drug delivery systems. The opportunities and challenges of nanotechnologies in drug delivery to overcome current disadvantages are also discussed. Furthermore, we have added findings regarding the trends and perspectives regarding nanotechnologies for combinatorial anticancer drug delivery.

Recent research and development of local anesthetic-loaded microspheres

This review introduces the recent research and development in local anesthetic-loaded microsphere, as efficient microspheres formulation, the efficient microspheres: optimum preparation method, high loading efficiency, and ideal release rate.

Montelukast Nanocrystals for Transdermal Delivery with Improved Chemical Stability

A novel nanocrystal system of montelukast (MTK) was designed to improve the transdermal delivery, while ensuring chemical stability of the labile compound. MTK nanocrystal suspension was fabricated using acid-base neutralization and ultra-sonication technique and was characterized as follows: approximately 100 nm in size, globular shape, and amorphous state. The embedding of MTK nanocrystals into xanthan gum-based hydrogel caused little changes in the size, shape, and crystalline state of the nanocrystal. The in vitro drug release profile from the nanocrystal hydrogel was comparable to that of the conventional hydrogel because of the rapid dissolution pattern of the drug nanocrystals. The drug degradation under visible exposure (400–800 nm, 600,000 lux·h) was markedly reduced in case of nanocrystal hydrogel, yielding only 30% and 50% amount of cis-isomer and sulfoxide as the major degradation products, as compared to those of drug alkaline solution. Moreover, there was no marked pharmacokinetic difference between the nanocrystal and the conventional hydrogels, exhibiting equivalent extent and rate of drug absorption after topical administration in rats. Therefore, this novel nanocrystal system can be a potent tool for transdermal delivery of MTK in the treatment of chronic asthma or seasonal allergies, with better patient compliance, especially in children and elderly.